Windows only: Google Desktop 5.0 lets you search your PC, adorn it with gadgets, keep it secure and much more.

Among the highlights of this new version is an expandable preview window that appears on the Desktop search results page. This allows you to peek inside documents and data files without actually having to run the associated application. (To put it another way, you can see if a particular Word file is the one you really wanted, without having to launch Word.)

Google Desktop 5.0 also sports a redesigned, flashier sidebar with some overhauled gadgets and a much slicker Add Gadgets interface. (Much as I hate to say this, everything looks more Vista-like—but that's a good thing.) Finally, the new Desktop promises better security, alerting you when you're about to visit a possible phishing site or install malicious software.

If you're already a Google Desktop user, the new version is a no-brainer update. If you're an XP user who's been tempted by Vista's Sidebar, look no further than Google's robust alternative—which also happens to be a fine desktop-search tool. Finally, don't forget to check out Adam's excellent feature, Get more from Google Desktop.